Nearly thirty years ago, in the fall of 1986, Mordechai Vanunu, a low-level technician at Israel’s Dimona nuclear reactor, left Israel for a trip to the Far East. He settled in Australia, converted to Christianity, and sometime in August that year began to talk with Peter Hounam, a London Sunday Times reporter, about what he saw at Dimona. He spent eighteen years in jail, eleven of these years in solitary confinement, and was released, under severe restrictions, in 2004. Last Thursday he was detained in Jerusalem for violating one of his release conditions: he talked with two foreigners, that is, non-Israelis, for more than half-an-hour.

Nearly thirty years ago, in the fall of 1986, Mordechai Vanunu, a low-level technician at Israel’s Dimona nuclear reactor, left Israel for a trip to the Far East. He settled in Australia, converted to Christianity, and sometime in August that year began to talk with Peter Hounam, a London Sunday Times reporter, about what he saw at Dimona.

The Sunday Times flew him to Lindon for more in-depth interviews, in which Vanunu described how Israel has mastered lithium-6 separation process, which is required for the production of tritium. Tritium is an essential ingredient of fusion-boosted fission bombs.

The Times asked two nuclear experts – Theodore Taylor and Frank Barnaby – to examine Vanunu’s information, and both said it was credible. Vanunu described in detail the plutonium processing Israel was using, saying the production rate was about thirty kilograms per year. He further stated that Israel used about four kilograms per weapon. Based on these figures, Taylor and Barnaby estimated that Israel had accumulated sufficient plutonium for about 150 nuclear weapons.

Israeli intelligence learned of his conversations with the Times – but also with the Mirror. There had been persistent rumors that Israel was tipped by Robert Maxell, the publisher of the Mirror who was, apparently, also working for the Mossad (Maxwell committed suicide in November 1991 after it was revealed that he had fraudulently misappropriated money from the Mirror Group pension fund).

The Mossad wanted to grab him and bring him back to Israel to stand trial – but did not want to kidnap him in London because of the good relationship Israel had with Margaret Thatcher.

Even before the Vanunu revelations were published in England in late October, a blonde Mossad agent lured him to go with her to Italy for a romantic excursion. When they entered her apartment in Rome, he was overpowered by waiting Mossad operatives who drugged him, smuggled him out of Italy, and brought him to Israel.

In 1988, in a behind-closed-doors trial, Vanunu was sentenced to eighteen years in prison, and he spent eleven of these years in solitary confinement.

He was released in 2004, but was placed under exceedingly strict restrictions – among them a prohibition on talking with foreigners, that is, non-Israelis.

In December 2014 Vanunu appealed this particular restriction, and the commander of the Home Front Command, Maj. Gen. Eyal Eisenberg, agreed to ease the restriction somewhat. Under the new conditions, Vanunu is still not allowed to speak with foreigners, but he is allowed to “hold a chance conversation in person with foreign citizens or foreign residents, as long as it is a one-time conversation that is held face-to-face, not planned in advance, takes place in a public space open to the general public and which lasts for a period of no more than thirty minutes.”

Haaretzreports that last Thursday, Israel’s Independence Day, Vanunu disappeared. Worried friends and acquaintances searched for him, but the mystery was not solved until the next day. It appears that Vanunu was arrested by seven Border Police officers and a female police officer after they watched him hold a conversation with two foreigners for they considered to be more than half-an-hour – a violation of his release conditions.

Vanunu’s lawyer said his client was at the international book store at the American Colony Hotel in Jerusalem. He exchanged a few words with two tourists who happened to enter the store. The police, apparently watching Vanunu and timing the conversation, entered the store and took him with them to a police station.

The lawyer said that Vanunu and the police interrogators engaged in a lengthy discussion over the question of how long the conversation in the bookstore went on, whether it lasted more than thirty minutes, and how the calculation should be made: Vanunu was speaking with two people, so one of the questions was whether or not Vanunu’s exchanges with each individual should be clocked separately, meaning that Vanunu was entitled to a 1-hour conversation — one half-hour with each of the two tourists at the store.

Civil libertarians and legal experts say that the Israeli government, out of sheer vengeance, mistreats and harasses Vanunu even after though he had served his time. They, and people in the know, also note that whatever information Vanunu has is obsolete, since the last time he set foot inside the Dimona reactor was three decades ago.

Still, the issue of nuclear weapons is a taboo in Israel – it cannot be broached or discussed. It appears that Vanunu is being punished – some would say, persecuted – not because he revealed any military secrets (how many of Israel’s adversaries have any doubts about Israel’s nuclear arsenal?), but because he committed an even more serious offense: he violated a sacred societal taboo.